Amazon EFS Limits That You Can Increase

You can increase the following Amazon EFS limit by contacting AWS Support.

Resource

Default Limit

Number of file systems for each customer account in an AWS Region

1,000

You can work with the following throughput limits by using the throughput mode that
you
choose for your file system, Bursting or Provisioned. For more information on these
different
modes, see Amazon EFS Performance.

Resource

Default Limit

Total bursting throughput for all connected clients

US East (Ohio) Region – 3 GB/s

US East (N. Virginia) Region – 3 GB/s

US West (N. California) Region – 1 GB/s

US West (Oregon) Region – 3 GB/s

Asia Pacific (Seoul) – 1 GB/s

Asia Pacific (Singapore) – 1 GB/s

Asia Pacific (Tokyo) – 1 GB/s

EU (Frankfurt) Region – 1 GB/s

EU (Ireland) Region – 3 GB/s

EU (London) Region – 1 GB/s

Asia Pacific (Sydney) Region – 3 GB/s

Total provisioned throughput for all connected clients

All AWS Regions – 1 GB/s

You can take the following steps to request an increase for these limits. These increases
are not granted immediately, so it might take a couple of days for your increase to
become
effective.

Limits for NFS Clients

The following limits for NFS clients apply, assuming a Linux NFSv4.1 client:

The maximum throughput you can drive for each NFS client is 250 MB/s.

Up to 128 active user accounts for each client can have files open at the same time.
Each user account represents one local user logged in to the instance. A user account
that
is logged in multiple times counts as one active user.

Up to 32,768 files open at the same time on the instance. Listing directory contents
does not count as opening a file.

Each unique mount on the client can acquire up to a total of 8,192 locks across a
maximum of 256 unique file/process pairs. For example, a single process can acquire
one or
more locks on 256 separate files, or 8 processes can each acquire one or more locks
on 32
files.

When connecting to EFS, NFS clients located on-premises or in another AWS region can
observe lower throughput than when connecting to EFS from the same AWS region due
to
increased network latency. Network latency of 1 ms or less is required to achieve
maximum
per-client throughput. Use the AWS DataSync data migration service when migrating
large
data sets from on-premises servers to Amazon EFS.

Using Amazon EFS with Microsoft Windows is not supported.

Limits for Amazon EFS File Systems

The following are limits specific to the Amazon EFS file systems:

Maximum name length: 255 bytes.

Maximum symbolic link (symlink) length: 4080 bytes.

Maximum number of hard links to a file: 177.

Maximum size of a single file: 52,673,613,135,872 bytes (47.9 TiB).

Maximum directory depth: 1000 levels deep.

Any one particular file can have up to 512 locks across all instances connected and
users accessing the file.

In General Purpose mode, there is a limit of 7000 file system operations per second.
This operations limit is calculated for all clients connected to a single file
system.

Unsupported NFSv4 Features

Although Amazon Elastic File System does not support NFSv2, or NFSv3, Amazon EFS supports
both NFSv4.1 and
NFSv4.0, except for the following features:

pNFS

Client delegation or callbacks of any type

Operation OPEN always returns OPEN_DELEGATE_NONE as the delegation
type.

The operation OPEN returns NFSERR_NOTSUPP for the
CLAIM_DELEGATE_CUR and CLAIM_DELEGATE_PREV claim
types.

Mandatory locking

All locks in Amazon EFS are advisory, which means that READ and WRITE operations do
not
check for conflicting locks before the operation is executed.

Deny share

NFS supports the concept of a share deny, primarily used by Windows clients for users
to deny others access to a particular file that has been opened. Amazon EFS does not
support
this, and returns the NFS error NFS4ERR_NOTSUPP for any OPEN commands
specifying a share deny value other than OPEN4_SHARE_DENY_NONE. Linux NFS
clients do not use anything other than OPEN4_SHARE_DENY_NONE.

Access control lists (ACL)

Amazon EFS does not update the time_access attribute on file reads. Amazon EFS
updates time_access in the following events:

When a file is created (an inode is created).

When an NFS client makes an explicit setattr call.

On a write to the inode caused by, for example, file size changes or file metadata
changes.

Additional Considerations

You mount your file system from EC2 instances in your VPC by using the mount targets
you create in the VPC. You can also mount your file system on your EC2-Classic instances
(which are not in the VPC), but you must first link them to your VPC by using ClassicLink.
For more information about using ClassicLink, see ClassicLink in the
Amazon EC2 User Guide for Linux Instances.

You can mount an Amazon EFS file system from on-premises data center servers using
AWS Direct Connect
and VPN.